Pump



G. E. GALL PUMP 5 SheetsSheet l Filed Jan. 31, 1944 Y @naga Sept. 117, 1946.. Q E GALL 2,407,923

PUMP

Filed Jan. 3l, 1944 3 Sheets-Sheet 3 Patented Sept. 17, 1946 PUMP George E. Gall, Chicago, Ill., assignor to Anker- Holth Manufacturing Company, Inc., Chicago, Ill., a corporation of Michigan Application January 31, 1944, Serial No. 520,391 7 Claims. (Cl. 10S-10) This invention relates to a pump, and more particularly to a hydraulic pump for delivering liquid under pressure. The pump may be used for operating hydraulic cylinders to furnish power for various appliances, and can be utilized wherever it is desired to supply hydraulic pressures.

An object of the invention is to provide a pump which will deliver liquid at high pressures when high pressures are required for the work being done, and which will develop these high pressures without the objectionable pulsations or vibrations which are commonlyassociated with such operation. Y

Another object of the invention is to provide a pump of this character which is capable of developing very high pressures, but which at the same time will deliver liquid at a rapid rate during periods of operation in which high pressures are not required, so that an overall operation involving periods of low pressure operation and periods of high pressure operation may rbe performed in a minimum of time. A further object is to provide a pump capable of quickly delivering the liquid necessary for performing an operation which requires high liquid presures, at least during some periods of the operation, while at the same time keeping to a minimum the power required to actuate the pump.

Another object is to provide effective means for cutting off the delivery of liquid delivered by the pump under high pressure while the pump remains in operation. It is desired that such cutoi means shall be easy to operate and maintain and that it shall not be subject to wear through erosion when in operation.

A further object is to provide a pump unit which is compact and has all moving parts readily accessible.

Other objects and advantages will be apparent as the specification proceeds.

An embodiment of the invention is illustrated in the accompanying drawings, in which- Fig. 1 is a perspective view of a pump fully assembled; Fig. 2 is a plan sectional view taken as indicated at line 2-2 of Fig. l; Fig. 3 is an elevational sectional View taken as indicated at line 3--3 of Fig, 2; Fig. Il is an elevational sectional view taken as indicated at line 4-4 of Fig. 2; and Fig. 5 is an elevational sectional View taken as indicated at line 5-5 of Fig. 2.

As illustrated, the structure includes a pufmp body l e to which is secured the iront bearing cap I I and the rear bearing cap I2. Screws I3 serve to fasten these caps tight against the pump body.

The pump body and caps may be ings of any suitable metal. 1 A drive shaft I4 extends through the structure, being journaled in the bearing I5 in the front cap I I and driven by any suitable source of power such as the electric motor I1 shown in Fig. 1.

Inside the front cap I I, and shown more clearly in Fig. 4, is a low pressure pump section A which includes the gear I8 mounted on the shaft I4. Located above and in meshed relationwith gear I8 is a second gear I9 mounted on shaft 20 which has its one end journaled in the bearing 2I carried in the body I0 and which has'its other end journaled in the bearing 22 carried in the front cap I2.

A passage 23 leads from an opening ,24 in the top of the pump body Il] to the gears I8 and I9. A second opening 25, which is in the side of the body Ill, also communicates with the passage 23. One of the openings 24 and 25 may be plugged and the other may be connected by conduit with any suitable source of liquid.

When the pump section A is in operation, with the shaft I4 turning in a clockwise direction as seen in Fig. 4, the gears I8 and I9 function under well-known principles to draw liquid from the passage 23 and pass it between the gears and on through the passage 26.

Passage 26 communicates with passage 2l leading rearwardly in the body IU (shown in dotted lines in Fig. 2), and passage 2'I communicates with the passage 28 which leads upwardly to the opening 29 at the top of the body I0 (see Fig. 3)

formed of cast- For controlling the pressure developed by the low pressure pumping section A, there is provided a pressure regulating apparatus 30. This apparatus includes the plunger 3I carried in the cylindrical cavity 32 of the body IU, which cavity l communicates at its bottom with passage 23. The upward movement of the plunger 3| is resisted b-y the spring 33, the upper end of which bears against the centering piece 34, which in turn bears against the bottom of adjusting screw 35 carried in the nut member 35. A cap 31 carried on the nut member serves to enclose the screw 35. l

A passage or conduit 38 leads from cavity 32 to an opening in the top of body I0, which opening may be connected by suitable conduit with a low pressure liquid receiver which may be the same as the liquid source with which the inlet passage 231s connected. As seen moreclearly at Fig. 4 of the drawings,V when the `plunger 3l is moved upwardly against the spring 33 to bring y the valve $9 for the return of 3 the mouth of the conduit 38 into communication with the lower part of the cavity 32, a part of the liquid delivered by the pump section A may be by-passed through the conduit 38 and led through other suitable conduit back to the liquid source.

The apparatus may be adjusted by turning the adjusting screw to permit greater or lesser pressure to be developed by the pump section A as may be desired. When the screw is turned to a lower position, this requires a greater liquid pressure on the bottom of the plunger 3| to raise the plunger suiciently to allow liquid to be ley-passed through the passage 38.

Communicating with the passage 23 is a side conduit Bil which leads to thevalve cavity :il (see Fig. 3). In this cavity is the valve l2 including a ball 43 pressed by spring 44, the top of which is held by the plug 65. The valve arrangement is such as to permit liquid to pass from the pas'- sage @il into the valve cavity, but to prevent the back ow ci liquid from the valve cavity into the passages 49 and 28. The valve cavity 45 communicates through the passage llt with thel cylnder 5i! of the high pressure pump section B.

g :The highpressure pump section B;.(see Figs, 3

and 51)is. driven through the rotation of the shaft,I i4 on which is mounted the eccentric El. TheV shaft is journaled inthe bearings le and 52V on-'eacbside of. theeccentric 5l. The cylinder 55 extending verticallyy above, the eccentric 5I is lined with a lbushing 56 and apiston ,53 is mounted for reCproCal movement within the cylinder. The base ofk piston 5.3 rests on the bearing 54 of the eccentric El and is adapted to be moved in reciprocal motion through actuation by rotation of the eccentric. 'Access to the cylinder is provided by the plugged opening 51 at the top, and a plugged opening 5B, allows access to the eccentric. Anvout'let from the high pressure section is provided by the passage 6i] leading from the passage d6 (see Fig. 2). Passage 6U leads through the valve structure 6I to the conduit 62 which may lead to the pump outlet. The valve structurel Ell) includes a cavity 53 in which is located the ball B4 and spring 65, the arrangement being` such as to prevent iiow of liquid from the pump outlet back into the high pressure pump section.

A passage I0 leads from the top of cylinder 55 and connects through the valve structure 'il with a conduit 'l2 which may lead through needle valve 'i3 (Fig. l) to a low pressure liquid receiver, suitably the liquid source from which liquid is drawn into the inlet passage 23 of the low pressure section. The opening of the valve 'H3 serves to permit flow of liquid through passage 'lll and conduit 'l2 to relieve the pressure in the outlet of the high pressure section and stop delivery of liquid under pressure though the reciprocating apparatus of this section continue to operate.

The pump body Hl, with'the caps il and l2 attached, may be mounted on the base 80, as shown in Fig. 1, and set on top of a housing 82 which may contain a receptacle holding a supply of oil, or other liquid. rIhe motor l1 is arranged with its drive shaft in drive connection with the shaft I4. As shown in Fig. 1, the pipe S3 connects the low pressure discharge opening 29 with valves B and 85, which in turn connect with conduits S6 forming the outlet of the pump. In this par@ ticular set-up, a gauge 87 is provided for indieating the pressure developed by the low pressure section.

The pipe Se provides a passage controlled by liquid back to the source for reuse.V f f i The conduit $2 connects the outlet of the high pressure section to the pipe 86 which forms the pump outlet and leads to the particular appliance receiving the hydraulic power. The conduit 'l2 containing the valve 'i3 is connected to the pipe 88 which, as before explained, leads back to the source of liquid supply in the housing 82. rThe inlet conduit 9| has its one end connected with the inlet opening 2li and its other end connected with the source of liquid supply. The conduit 9@ connects the passage 38 with pipe 88 leading back to the liquid source.

When the improved pump is started in operation, the valves 'l2 and 89 are closed, and the rotation cf shaft Iii powered by motor Il serves to actuate both the low pressure section and the high pressure section. The rotation of gears I8 and l of the low pressure section serves to draw liquid from the source through the conduit 9i and passage 23, and to pass liquid under pressure through the passage 26. Frompassage 26, the liquidv passes consecutively through passages 2l and Z, and is led through pipe 83 from which it passes through valves 84 and 85' to the outlet of the pump. The construction of this low Ypressure section permits the delivery of liquid at a relatively rapid rate. However, when the pressure builds up substantiallyrat the pump outlet, liquid is no longer delivered directly from the low pressure section tothe pump outlet, A.as above described.

Pressure at the outlet-of the low pressure section above a predetermined amount causes the plunger 3l to rise against the spring 33 to permit a small amount ofv liquid to be by-passed back to the' liquid source, and when a high pressure` is called forv at the pump outlet so that no liquid can'be delivered directly through pipe 83, the plunger rises still further so that a major portion or" the liquid passed by the gears is ley-passed back to the source. In this way, the pressure of the liquid at the outlet of the low pressure section is maintained at a substantially constant level, irrespective of how mu'ch `of the liquid passed therethrough is delivered to the pump outlet.

At the same time that liquid is being delivered to the pump outlet through operation of the low pressure section to build up the pressure at the pump outlet, the high pressure section will also have been Vin. operation, and rotation of the eccentric l will have produced reciprocationof the piston 53. The retraction or downward movement of' piston 5.3y will permit liquid tb pass through the' valveI ft2, impelledby the pressure developed by the low pressure section, and the following advancement or upward movement of the .piston will force the liquid Awhich has entered through valve i2 out through the passage 6), valve 6i and conduit 62 to the pump outlet. However, until the pressure atthe pump outlet has built up, the liquid delivered through the conduit e2 from the high pressure section will be small in comparison to the volume of liquid delivered thro-ugh the pipe 83 from the low pressure section. When the pumpfoutlet pressure is high and ful-l power is needed, the low pressure section, as bei-ore stated, ceases to deliver liquid to the pump outlet, and at this point the operation of the high pressure sectionbecomes of importance. The liquid under the relatively .low pressure developed by the low pressure section passes through the valve i2 and out by way of valve 6l andconduit 62to the pump outlet impelled by the advance stroke of therecprocating piston. Y .Y

Constructed as it is, the improved pump is able to deliver at a rapid rate during periods when high power is not required, and when high power is required is able to deliver under high pressure. This makes the pump extremely versatile, and it may be'actuated With a relatively small motor. For example, a pump of this construction powered by a 1/2 H. P. electric motor may develop a pressure of about 3,000 pounds per square inch.

An important feature of the improved pump is that the high pressure section is arranged in the liquid flow circuit in series with the low pressure section. In this Way, pressure is vmaintained on the piston as it moves in its downward or reverse stroke, and the objectionable pulsations common in high pressure systems heretofore used are eliminated. By the improved construction, the movement of the piston is smooth and regular, and the usual vibration caused by reversal of pressure on the piston at the change of the stroke is avoided.

It is not necessary to use special oils or other special liquid in the improved pump, and ordinary motor oil may be used. Cooling of the oil usually required on other high pressure systems is not here essential.

The means provided in the improved construction for stopping now of oil under high pressure is advantageous in that the usual valve in the high pressure line is eliminated. A needle valve in a high pressure line is a source of trouble and is subject to considerable wear since the liquid passing through causes erosion. In the improved structure, the pressure is relieved the moment liquid starts to pass through the valve '13, and erosive Wear is substantially avoided.

In the foregoing description, a-single embodiment of the invention has been described in great detail. It must be understood that this detailed description has been given for purposes of explanation only, and that the invention may be practiced in many modified forms, and many changes may be made without departing from the spirit of the invention.

In the foregoing explanation and in the claims, the terms high pressure and low pressure are used in a relative sense to describe the pressures developed by the one pumping section With relation to those developed by the other pumping section, and not for the purpose of designating any particular range of pressures.

I claim:

l. A pumping unit having a main outlet and comprising a high and low pressure section eachl having an outlet communicating with said main outlet, said low pressure section having its outlet connected also with the inlet of said highpressure section and being adapted to deliver liquid to said main outlet at a relatively fast rate so long as the pressure at said main outlet does not exceed a predetermined pressure, said low pressure section being also adapted to deliver liquid to said high pressure section when the pressure of said main outlet is in excess of said predetermined amount, a shaft for driving both of said pumping sections, a valve preventing backflow of liquid from said main outlet to said high pressure section, and a valve preventing backow of liquid from the inlet of said high pressure section to said loW pressure section.

2. A pumping unit having a main outlet and comprising a high pressure pumping section including a reciprocating pumping apparatus the outlet of Which is connected to said main outlet and including valve means for preventing llow of liquid' from said main outlet back to said reciprocating pumping apparatus, a low pressure pumping section including a rotary gear pumping apparatus, pressure regulating means for maintaining the pressure of liquid at the output of said low pressure section at a substantially constant level, a conduit system connecting the output of said lovv pressure section with the outputof said pump and connecting also the output of said low pressure section with the inlet of said htigh pressure section, a valve preventing flow of liquid from said main outlet back to said low pressure section, a valve preventing now of liquid back from said high pressure section to said low pressure section, and means for driving both of said pumping sections.

3. A pumping unit having a main outlet and comprising a high pressure pumping section with its outlet connected to said main outlet, a valv preventing the flow of liquid from said main outlet back to the outlet of said pumping section, and means for stopping the delivery of fluid under pressure to said main outlet While said pumping section is in operation comprising a conduit connecting the outlet of said pumping section to a low pressure area, a valve for preventing backovv of liquid from said low pressure area to the outlet of said pumping section, said last mentioned Valve being adapted to prevent free ow of liquid from said outlet to said low pressure area, and a valve selectively operable to open and close the passage in said conduit for controlling the passage of liquid through said conduit.

4. A pumping unit having a main outlet and comprising a high pressure pumping section including a reciprocating pumping apparatus the outlet of which is connected to said main outlet and including valve means for preventing iiow of liquid from said main outlet back to said reciprocating apparatus, means for stopping oW of liquid from said reciprocating apparatus to said main outlet, said means including a conduit connecting the outlet of said reciprocating pumping apparatus to a low pressure area, a valve preventing backflow of liquid from said area to said pumping apparatus outlet, and a valve selectively operable to open and close the passage in said conduit for controlling the passage of liquid through the conduit, a low pressure pumping section including a rotary gear pumping apparatus, a conduit system connecting the outlet of said rotary gear pumping apparatus to said main outlet and also to the inlet of said reciprocating pumping apparatus, a valve preventing iiow of liquid from said main outlet back to said rotary gear pumping apparatus, a valve preventing flow of liquid from said reciprocating pumping apparatus back to said rotary gear pumping apparatus, and means for preventing the rise of pressure at the output of said low pressure pumping section beyond a predetermined amount when the fioW of liquid through said conduit system to said main outlet diminishes.

5. .A pumping unit having a main outlet, comprising a high pressure pumping section including a reciprocating pumping apparatus the outlet of Which is connected to said main outlet and including valve means for preventing flow of liquid from said main outlet back to said reciprocating apparatus, means for stopping flow of liquid from said reciprocating apparatus to said main outlet, said means including a conduit connecting the outlet of said reciprocating apparatus to a low pressure area, a valve preventing backiiow of liquid from said area to said pumping appaoutlet, a Valve seleetively operable to .open and elose the passage in saidl conduit for `eontrolline the passage of liquid through the eondnit, low pressure pumping apparatus, a conduit systeni oonneeting the .outlet of said low pressure pumping apparatus vto the inlet of said reciprocating pumping apparatus, and a Valve preventing flow of liquid from said reciprocating pumping apparatus back to said low pressure pumping apparatus.

6, A pumping unit having a main outlet and comprising pumping means for maintaining a supply of liquid at a substantially constant low pressure, a reciprocating pumping section having its inlet connected to theoutlet of said pumping means and having its outlet connected to said main outlet,y said pumping section being eiective for delivering liquid to said main outlet atl relatively high pressure, a, rotary drive shaft connested with said pumping means Yand adapted to drive the same, and a kcam on said shaft for driving said reciprocating pumping section upon rotation Vof said shaft.

7. A pumping unit as set ,forth in claim 6 wherein said driving shaft includes a single shaft extending into both said pumping means and said reciprocating pumping section.

' GEORGE E. GALL. 

